feat(duplication): support duplication entry for multiple purposes

[empiredan]

duplication_entry is an important struct for duplication, including per-duplication
properties and progress info(confirmed decree) for each partition of a table. It
contains all useful info for a duplication. Therefore, it has been used in response to
query and sync:

• The query is requested by client, to the meta server to get the properties of
  duplications of single table;
• The sync is requested by replica server, also to the meta server to sync progress.

Soon we would support a new interface to get duplications from multiple tables,
i.e. list duplications. It would request duplications of multiple tables, also including
per-duplication properties and progress info(confirmed decree and a new field last
committed decree). It still uses duplication_entry as the response to the client.
Thus we add fields to duplication_entry to support more purposes.